turbo upgrade between t04e and gt35r?

[Koryu]

I'm looking for 400 whp and I see the t04e 50 trim gets close and the gt35r on jeffp is almost 500. I'm getting a senza pari intake manifold and I plan on port and polishing the head and changing the camshaft to pull to 6500-7000 rpm. Stock l28 bottomend p90. Planning on megasquirt 3 with cop. Possibly gonna run e85, haven't made up my mind yet. Would the gt3076r fit the bill??

[Chris83zxt]

Going by the maps I've studied of various compressors, the GT3076r can be a very good match for our motors stock up to moderate flow improvements.  500hp might be a stretch though.  400hp shouldn't be a problem.  The T04e-50 can make it to those levels (400hp) but it will be working a lot harder and getting a lot hotter to do it.

 

If I had had the money sitting around burning a hole in my pocket yesterday afternoon when my T3 bit it I would have ordered a 3076r without a second thought.

[Koryu]

That's what I was thinking to. I saw wigen-out got very close to 400 whp and maybe with some mods he could get there but that is maxing it out. I was looking for that mark with room to grow. The gtx3076r is pretty close in price to a gt3076r but I see the gtx flows more and seems like what I'm looking for. I know port and polish work and a cam will shift the knee points to the right on the graphs, just hard to tell by what margin and was hoping someone else had any experience with these 2 turbos or another recomendation. Thanks chris.

[Gollum]

If you're considering E85 you can pretty much consider that a solid 20%, if not more, increase in power potential from a given setup. This is given the assumption you've stopped raising boost due to heat. PSI for PSI you'll probably only see a net increase of about 3-5%, but with slightly faster spool times, increasing mid range HP.

 

The downsides?

 

It doesn't like to start a cold engine, and if you're running the turbo longlock 7.4:1 getting it to cold start will be fun to say the least. Most STI's @ a 8:1 compression spew a black cloud once they finally start on E85 since it takes such a huge amount to get it started. Why? Because alcohol needs HEAT to burn with significant energy. That's why we like it. It's heat requirement is exactly related to the heat it REMOVES from your combustion charge, another reason timing gets PULLED with E85, because the burn is slower due to the lower temps. So getting E85 started on a cold morning is actually relying on the gasoline content of roughly 15%, which takes a LOT to near your E10 variety of fuels.

 

Another serious downside is that if you need to USE it, or STORE it! If it absorbs as much as 2% water (which it will sitting open to atmosphere) then it starts becoming extremely corrosive. Even aluminum will start to pit if you let this happen. If you plan to keep things open to atmosphere for any significant time you need to have stainless EVERYTHING, and pray it doesn't eat your injectors. The solution is to have an airtight system with valve going to the vacuum lines so you can seal it up when left to sit. If you're worried about temperature expansion/contraction you an install a large pressure relief plate that's just a diaphragm with a spring allowing changes in volume to act against the spring instead of warping your tank.

 

Injectors need to be large. I mean LARGE. You need to be ready to run down to 6:1 AFR (yes the damn fuel will still run down there and make power, even those stoich is 9.7. That's lambda .62 at which point gasoline would be at a mere 9.1:1! That also puts you at nearly twice the injector size requirement. For 400 whp I would recommend not even considering going anywhere less than a 1000cc injector. Gasoline injector requirements would be around 600cc give or take depending on BSFC and fuel pressure, and if you wanted to run "similar" lambda numbers then you only need about a 800cc E85 injector... but why do that? The point of E85 is that it doesn't misfire when you go rich, and it doesn't foul plugs. So you add extra fuel as a cooling agent, which helps stabilize the burn and prevent detonation. That is why you need huge injectors. Don't be afraid to tune that sucker RICH under boost.

 

 

Now, regarding turbo choice. I think the GTX3076 is a wonderful choice, especially on E85. That combination should get to your goals with relative ease. If running pump gas I think it'd make it, but I'd want a larger turbo if I was running it under boost for long periods, like at a HPDE event. If drag racing? No worries. Street car? No worries. But that turbo will be getting quite hot over time at those levels. At 400 whp you're approximating 475hp, or roughly 45-55 lb/min worth of air, depending on VE. If this is a relatively stock head I'd bet closer to the 55 lb/min end of that guess. You're also going to be around... 30-32psi with a stock head. Maybe higher actually. Look at that area of the GTX3076R's map... You're starting to get pretty high, and due to the compressor's size you might be flirting with surge depending on how soon it spools on you.

 

But, you're going to be running the new whiz-bang senza intake (did I spell that right? Sorry if I didn't). If you're doing some BASIC head work to match, and making sure to do the appropriate port work on the exhaust manifold side, then things start to change. Are you running flat top pistons? If so that starts to change some things too. Moving the peak HP up just 500rpm makes a WORLD of difference. Now you're only expecting about 26-27psi which gets you that much closer to and ideal match with this turbo. If we assume that a stock 7.4:1 untouched chamber is about a .55 BSFC and an unshrouded and polished chamber with a 8.3:1 is just a mere 2 point imporovement to .53 BSFC that drops you down to around 25psi for expected boost levels. Now we're getting somewhere.

 

See, there's a butt ton of variables at play here, and unless you have a very good idea of what your VE curve looks like, and roughly what BSFC you'll be expecting, along with what fuel you're using and such, then it's extremely difficult to plot your engine against a compressor map.

 

But all that said, I certainly think the GTX3076 is large enough for your goals, because if you needed a larger turbo then you probably have some work to do on your head. At any rate is that 45-50 lb/min range you should be looking at on a compressor map, because that's about how much air you're going to need regardless of the pressure ratio. And in that sense, you're in the ballpark, and considering that you're on the further end of it's map it should spool nicely for all things considered (especially being a GTX series).

[Koryu]

No I'm running the dish pistons. I plan on port matching both the intake and exhaust and blending the bowls and cleaning up the ports. I'm thinking about taking the valve guides down in the exhaust only to help with flow as it looks like a huge restriction. I'm hoping with the head work I described with a nicely match cam to pull to approx 7000, the ve should be to the point where I can use less psi for my goal while also keeping heat down. E85 sounds great, but I'm alittle worried about all of the work involved to have it. This will only be a weekend car, some track events like drag racing seldomly but mainly just a fun car on the weekends that can play with my friends with z06's. I was thinking the gtx would be a good match, I like the way the 50 trim .63 looks, and I just wanted a little more and this looks like it fits the bill

[Gollum]

By the way, for my E85 install I plan to run a dual injection setup, running pump gas off boost and E85 on boost. This makes things slightly MORE complicated in some ways, but it simplifies others.

 

More complicated:

 

• Need extra injector bosses, fuel rail, tank, pump, etc.
• Two totally different fuels to tune (but not any different than having a dedicated race fuel table set)
• Double expense on many parts, like injectors
• Your ECU needs to support it decently well (I'll be running MS3X)

 

Less Complicated:

 

• No need to be worried about cold start issues
• Because the engine shuts down on pump gas there's no chance of corrosive alcohol being left in the cylinders that might by chance start corrosion
• E85 tank can be smaller with a simpler mounting arrangement

 

This also has the added benefit that if you're on a trip and you run out of E85 you can just force the wastegate open and drive easy on it and make it home on pump gas.

[Koryu]

That sounds good. Just like running a GM flex fuel vehicle. I will give it some thought on the e85 and I also will be running m3x. Thanks for your inputs.

[TimZ]

 

It doesn't like to start a cold engine, and if you're running the turbo longlock 7.4:1 getting it to cold start will be fun to say the least. Most STI's @ a 8:1 compression spew a black cloud once they finally start on E85 since it takes such a huge amount to get it started. Why? Because alcohol needs HEAT to burn with significant energy. That's why we like it. It's heat requirement is exactly related to the heat it REMOVES from your combustion charge, another reason timing gets PULLED with E85, because the burn is slower due to the lower temps. So getting E85 started on a cold morning is actually relying on the gasoline content of roughly 15%, which takes a LOT to near your E10 variety of fuels.

I agree with most of what was said here, but I think that the cold start issue isn't quite as bad as it sounds above, depending on what we are considering "cold start".  I'm running 7.5:1 with a pretty aggressive cam, and on a 60degF morning cold start, my engine starts right up with no drama or clouds of black smoke - actually I've never seen E85 burn black at all.  This last weekend it started up with a bit more effort than usual on a ~50degF cold start, but it did still start pretty easily, and with no clouds of smoke.  It is a bit more cantankerous until it warms up in this weather, but it's bearable.  That said, if you are going to try to drive the car in actual winter weather E85 would not be the best choice and you will start having cold start issues when the ambient temps drop into the 40's or lower.  In regions where they have real winters, the "E85" is actually E70 in the winter months for just this reason.

 

Injectors need to be large. I mean LARGE. You need to be ready to run down to 6:1 AFR (yes the damn fuel will still run down there and make power, even those stoich is 9.7. That's lambda .62 at which point gasoline would be at a mere 9.1:1! That also puts you at nearly twice the injector size requirement. For 400 whp I would recommend not even considering going anywhere less than a 1000cc injector. Gasoline injector requirements would be around 600cc give or take depending on BSFC and fuel pressure, and if you wanted to run "similar" lambda numbers then you only need about a 800cc E85 injector... but why do that? The point of E85 is that it doesn't misfire when you go rich, and it doesn't foul plugs. So you add extra fuel as a cooling agent, which helps stabilize the burn and prevent detonation. That is why you need huge injectors. Don't be afraid to tune that sucker RICH under boost.

 

 

Again, mostly agree here, but AFRs of 6:1 would be a bit excessively rich, IMHO. 6.9:1 is about as rich as I would purposely go, and I'm currently seeing max power at more like 7.2:1.  I do start seeing misfire issues if I go below ~6.5:1.  I usually try to size things a minimum 50% larger than you would for an equivalent power target on gasoline.

 

To me the biggest drawback for E85 is availability (or lack thereof) in some areas.  Here in Michigan, we now have enough stations that I no longer worry too much about it.  Also, I went ahead and added a flex fuel sensor and use it to do a true flex fuel setup with my EMS (Electromotive TEC3r).  This makes it easier for me to simply switch back to gasoline when the weather turns cold, or if I get stranded somewhere that doesn't have E85.

 

It's working well and it was much less complicated hardware-wise than a dual fuel supply setup, but the tuning was _not_ for the faint of heart.  I'm willing to bet that I'm the only person to get this working well on a TEC3

 

Anyway - sorry if this was off-topic.  Back to your regularly scheduled posting...

Edited October 30, 2013 by TimZ

[Gollum]

Tim ~ what are you using for your spark again? Stock STI coils seem to withstand 6.5:1 pretty well, but they DO like to run pretty rich, even with the gasoline. I have a feeling your BSFC is quite a bit higher than most STI combinations (think about it, stock they'll put out a measly 165HP with 2.5 liters and HIGHER compression than the turbo variants... I bet your motor without a turbo would easily see 250+ at the crank, if not wheels...)

 

And yes, you're right. At 50-60 degrees it's not so bad starting cold. But even in the bay area nights dip well into the 30's at times, which makes starting the car before or near sunrise a challenge. Where I'm at now in Vacaville sub-freezing overnight temps are a normal occurrence, not a once in a while event. And regarding the smoke, alcohol just about always burns visibly clean, with near zero soot, so the black smoke I've seen multiple STIs spew has got to be large amounts of gasoline in the mix finally igniting.

 

And you'd be surprised how low on ethanol the mixes get even in the bay area. It's actually quite hard to find real E85 in the dead of winter, making those handy GM sensors nearly mandatory.

 

I'd love to chat about your experience with the TEC3 as I'm getting slightly more versed with the world outside of MS, but I won't clutter up this thread. Overall I think we're doing a decent job of giving the OP good on point info.

[TimZ]

Tim ~ what are you using for your spark again? Stock STI coils seem to withstand 6.5:1 pretty well, but they DO like to run pretty rich, even with the gasoline. I have a feeling your BSFC is quite a bit higher than most STI combinations (think about it, stock they'll put out a measly 165HP with 2.5 liters and HIGHER compression than the turbo variants... I bet your motor without a turbo would easily see 250+ at the crank, if not wheels...)

 

And yes, you're right. At 50-60 degrees it's not so bad starting cold. But even in the bay area nights dip well into the 30's at times, which makes starting the car before or near sunrise a challenge. Where I'm at now in Vacaville sub-freezing overnight temps are a normal occurrence, not a once in a while event. And regarding the smoke, alcohol just about always burns visibly clean, with near zero soot, so the black smoke I've seen multiple STIs spew has got to be large amounts of gasoline in the mix finally igniting.

 

And you'd be surprised how low on ethanol the mixes get even in the bay area. It's actually quite hard to find real E85 in the dead of winter, making those handy GM sensors nearly mandatory.

 

I'd love to chat about your experience with the TEC3 as I'm getting slightly more versed with the world outside of MS, but I won't clutter up this thread. Overall I think we're doing a decent job of giving the OP good on point info.

No problem - I was just concerned that your original post made it sound like _any_ time you try to do a cold start you were going to have problems, regardless of ambient temps.

 

I'm running the Electromotive 3-coil waste spark setup, so it's not particularly weak.  One other thing I found just this last summer that helped with startup was going back to BPR-7ES plugs, instead of the 8's I had been running.  Rule of thumb is to go another heat range colder for E85 (which never made that much sense to me), but when my 8's were running a bit rough I just thew in a set of 7's I had laying around and it's been running much better all around, and no issues with detonation.

 

My BFSC isn't particularly great either, every time I do the math it comes out more like 0.6 (gasoline) - I am running 7.5:1 after all. 

[Koryu]

I got a lot of new info in e85 that's for sure. Would I be good with 720 injectors then or 850's if running e85. Regarding the corrosive properties of ethanol, I'm having trouble finding a stainless surge tank, they all seem to be aluminum. But I think I saw an e85 additive that supposedly reduces the corrosive nature if I remember correctly. Anyhow I see the potential with e85 and given the l series is detenation prone anyhow, I think this is the way to go. I think I read somewhere a normal wideband does not work properly when using e85, and is it anymore difficult to tune using something like megasquirt?

[Gollum]

I've had plenty of success using the Innovative widebands with E85.

 

Regarding injector swapping, I think that's fine, BUT (there's that nasty word) injector flow modeling affects EVERYTHING in a tune so as much as you end up off on your first set of injectors you need to model off on the next which leaves you shooting after a moving target. One of the most important things in having a SOLID tune is knowing EXACTLY what your inputs and outputs are. If your IAT is off a touch, you need to know. If your MAP isn't exact, you need to know. You also need to know EXACTLY what your outputs do under static controlled conditions. This is why just plain flow charts for injectors don't impress me. When I buy injectors I also want to know (proven via scope) their open and close times, and I also want to know their flow compensation by voltage. Not all injectors lose flow the same as voltage drops, one more thing that can bite you while tuning.

 

For more info on the topic check this article, it's written by Greg Banish who writes my now favorite book on the subject because it's clear, concise, and to the point. His OEM background also means he's very methodical. He runs the website that hosts the file so you can check there for other info as well:

 

http://www.calibratedsuccess.com/Assets/Documentation/Fuel%20Injector%20Article.pdf

[TimZ]

I've had plenty of success using the Innovative widebands with E85.

 

Same here - perhaps you were confusing E85 with leaded race fuel?

[Chris83zxt]

I'll just confirm that the MTX-L does fine with E85, since most think LC-1 when Innovate widebands are brought up.

 

I'm going dual fuel via the GM flex sensor (the newest one that doesn't cost a fortune).  It's actually the lone sensor I have yet to hook up with my MS install, though it's already plumbed into the fuel system (suction side of pump).  I'll be doing it with 550cc injectors which I think will carry me up to 375hp or so safely(ish) on E85.

[Koryu]

Yea I could have gotten it confused with something else, for some reason I thought I heard that regarding e85 but that why I asked for clarification from you guys. The flex sensor sounds interesting..

[BLOZ UP]

The 35R is getting a bit on the large side, so pretty peaky. The T04E isn't bad, but the 3076 is the better choice if you're going smaller anyway.

[240Z Turbo]

I would recommend that if you are going to think about a GT3076r then you actually should consider running GTX3576r.  The GTX compressor wheel has similar inertia to the old wheel, but flows considerably more.  From my experience on the EVO there is no loss in spool going to the larger turbine wheel (35r vs 30r) and gains of 30-40hp can be achieved.  I am not saying the stage III to4e is a bad option and is definitely more cost effective, but there are better options from a performance standpoint.  If possible, I would also try to utilize a twinscroll setup to maximize spool.

[Tony D]

I agree with most of what was said here, but I think that the cold start issue isn't quite as bad as it sounds above, depending on what we are considering "cold start". I'm running 7.5:1 with a pretty aggressive cam, and on a 60degF morning cold start, my engine starts right up with no drama or clouds of black smoke - actually I've never seen E85 burn black at all. This last weekend it started up with a bit more effort than usual on a ~50degF cold start, but it did still start pretty easily, and with no clouds of smoke. It is a bit more cantankerous until it warms up in this weather, but it's bearable. That said, if you are going to try to drive the car in actual winter weather E85 would not be the best choice and you will start having cold start issues when the ambient temps drop into the 40's or lower. In regions where they have real winters, the "E85" is actually E70 in the winter months for just this reason.

 

It's working well and it was much less complicated hardware-wise than a dual fuel supply setup, but the tuning was _not_ for the faint of heart. I'm willing to bet that I'm the only person to get this working well on a TEC3

 

Anyway - sorry if this was off-topic. Back to your regularly scheduled posting...

Imagine at first a Zenith 32 NDIX, then a Weber 44IDF, and then finally a Weber 48IDA with weak carb preheat on pure Ethanol derived from Sugar Beets.

 

Don't underestimate how much easier this task is using EFI!

 

You may have done it with a TEC3.... Imagine if you can "cold start" at 70F with any of those on a cold, long runner manifold!

 

Been there, done that. Wish anybody else good luck! LOL

 

As to JeffP, he's spooling full boost at 3200 with his 35R an due to cast pistons currently in the mill is limited to 7400 (don't ask...) so not particularly "peaky". The area under the curve is impressive even using a stock cast piston L28ET bottom end.

Edited November 4, 2013 by Tony D

[Gollum]

As to JeffP, he's spooling full boost at 3200 with his 35R an due to cast pistons currently in the mill is limited to 7400 (don't ask...) so not particularly "peaky". The area under the curve is impressive even using a stock cast piston L28ET bottom end.

 

Which is HILARIOUS when you consider how many Honda D builds out there are thrilled to reach MIN boost at 3,000 with a redline of 7500ish.

[Koryu]

So basically I'm hearing that there is not any reason to run a gt30r because the gt35r will spool approx the same with more power output? I was trying to match the smallest turbo to the power output I want. The 35r seems like over kill but if the spool is close to the same as is the response then I get it but its just hard to believe is all.